Method of making tubes.



Patented 17 1917.

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WALLACE E. HUGHES, 0F PHILADELPHIA, PENNS YLVANIA.

METHOD or MAKING runes.

Specification of Letters Patent.

Patented Apr. 1'7, 1917.

Application filed September 14, 1915. Serial No. 50,6 37.

To all whom it may concern:

Be it known that I, WALLACE E. HUG-Hus, a citizen of the United States,residing in Philadelphia, Pennsylvania, have invented certainImprovements in the Method of Making Tubes, of which the following is aspecification. o

My invention relates to certain improvements in the process ofmanufacturing tubes of iron, steel, brass, copper, or other metal, andin the mechanism for carrying. out said process.

One object of the invention is to improve the process of making seamlessmetallic tubes.

A further object of the invention is to roll the tube flush on a mandrelas a core in asingle heat.

A still further object of the invention is to use a mandrel of a uniformdiameter throughout, .which is the form on which the tube is produced.

A further object is to produce tubes of a uniform diameter or tapered asdesired.

, Referring to the drawings, which are in Figure 1, illustrates amandrel on which is located the usual hollow ingot;

Fig. 2, 1s a view showing the tube in section after being rolled andprior to its I of a uniform diameter throughout and the size of theinterior of the tube to be formed. The mandrel may be of any lengthdesired. 2 is the hollow ingot from which the tube is made. This hollowingot is fitted on one end of the mandrel, as in Fig. 1, after beingheated to the degree required and is passed between the rolls 3, 3 withthe mandrel. These rolls may be the rolls of a 3-high stand or a 2 highstand, or may be the first rolls of a. continuous mill, according to theparticular mill in which my process 1s carried out.

The ingot is reduced to the proper diameter and gage flush with themandrel and of the length required during the rolling operatlon. Afterthe tube is rolled to the desired diameter it is acted upon to loosenthe mandrel, to allow it to be withdrawn from the formed tube.

One method which may be used to Withdraw the tube from the mandrel isto-hammer or tap the tube longitudinally at :r, or

longitudinally and circumferentially, with sufficient force to p: 'oducean enlargement or buckle 4 in the tube at one side, as shown in thedrawings. This causes the tube to draw away from the mandrel at thispoint.

Then, by rolling the tube laterally, the

buckle is carried a1 m nd it, which causes the tube to be slightlyonzarged so that the mandrel can be withdl awn. This enlargement isalmost imperce tible, yet is sufiicient to free the mandrel.

The lateral rolli 1g may be accomplished between two surfazes underpressure so as to carry the buckle entirely around the mandrel, as inFigs. 3 and 4 either in a straight line or spiral.

Recesses or slight projections may be formed on the surfaces which arearranged at an incline with I aspect to the longitudinal line of thetube, s) as to cause the tube to travel longitudinaly in order toprogressively press the tube to release it from the mandrel.

The abovedescri ption refers to a cylindrical tube, but my invention maybe carried out in making tul es oval, square, or other shapes in crosssec ;ion, using a particularly shaped mandred in the first step of theprocess and using a hai imer with the mandrel as an anvil to slightlyenlarge the tube dur ng the second step of the process.

By using a tap :red mandrel and so designing the passes of the rolls,the tube may be rolled tapered on the inside and outside, or either onthe inside or outside, as desired, and the outer cont an: of the tube atone end may beoval in closs section tapering toa round at the oppositeend; thetube tapered on the outside is limited inlength by thecircumference of the rolls.

By the use of my improved process, tubes may be made of greater lengthsand of a more uniform gag than heretofore and at a lower cost ofmanufacture, and limited as to length only by tl ethickness of the metalof the hollow ing OtllSGd and the capacity of the mill.

Tubes made 2.5 above described are I less tubes now made.

stronger, gage for ga e, than drawn seamhe tubes thus formedare-finished by any of the ordinary methods. If, for any reason, themandrel adheres to the tube then the tube can be iven a flash heat so asto expand the tube wlthout affecting the mandrel and then can be furthertreated to break the adhesion.

I claim 1. The process of making a seamless tube, said processconsisting in taking a hollow ingot, forcing the ingot over a mandrel ofa uniform diameter throughout and reducing the ingot to form a tube,then actin on the metal of the tube in alon itudina line so as toslightly enlarge the tu e, and then carthroughout and reducing the ingotto form a tube on said mandrel, then hammering ;th'e

tube on a longitudinal line so as to forma slight buckle or enlargementon the tube,

then rolling the tube laterally'to carry the buckle around the mandrel,freeing the tube therefrom, and finally withdrawing the mandrel from thefinished tube. WALLACE E'.;HUGHES.

